Active Time
20-30 minutes
Total Project Time
20-30 minutes
Key Concepts
Thermal expansion, temperature, measurements


Are you eager to understand how everyday items work, or interested in making useful objects and instruments yourself? Have you ever imagined you could build your own thermometer? In this activity, you will make a liquid thermometer to track how temperatures vary with location, indoors or outdoors. What will turn out to be the hottest spot in your home? What about the coolest? Your very own homemade thermometer will be able to tell you!


Sabine De Brabandere, PhD, Science Buddies
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.


  • Clear plastic drinking straw, preferably a 0.2 inch diameter straw.
  • Metric ruler
  • Fine-tipped permanent marker
  • Clean narrow-necked, small bottle with lid. Travel size bottles like these available from Amazon work well. Washed empty food coloring or vanilla extract bottles work well too.
  • Rubbing alcohol
  • A few drops or red, blue, or green food coloring. Liquid food coloring works best.
  • Paper or cloth towels
  • Modeling clay. Air-dry clay works well. Ultra-light modeling clay is easy to model and clean.
  • Medicine dropper or syringe
  • Water
  • Small bowl
  • Ice cubes
  • Optional: Store-bought thermometer

Disclaimer: Science Buddies participates in affiliate programs with Home Science Tools,, Carolina Biological, and Jameco Electronics. Proceeds from the affiliate programs help support Science Buddies, a 501(c)(3) public charity, and keep our resources free for everyone. Our top priority is student learning. If you have any comments (positive or negative) related to purchases you've made for science projects from recommendations on our site, please let us know. Write to us at


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Active Time
20-30 minutes
Total Project Time
20-30 minutes
Key Concepts
Thermal expansion, temperature, measurements
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